1
© WZL / IPT
Primary shaping - Casting
Manufacturing Technology II
Lecture 1
Laboratory for Machine Tools and ProductionEngineering
Chair of Manufacturing Technology
Prof. Dr.-Ing. F. Klocke
© WZL / IPT Seite 1
Structure of the lecture CastingIntroduction: Variety of applications
Basics of casting
Production sequence at casting
Production of casting patterns
Production of consumable moulds and cores
Casting processes
Case studies: Simulation during design and production
Case study: Rapid-Prototyping used at production of casting patterns
Comparison of costs
Summary
2
© WZL / IPT Seite 2
Introduction: Variety of applications- Survey of materials for casting and application examples
Basics of casting
Production sequence at casting
Production of casting patterns
Production of consumable moulds and cores
Casting processes
Case studies: Simulation during design and production
Case study: Rapid-Prototyping used at production of casting patterns
Comparison of costs
Summary
Structure of the lecture Casting
© WZL / IPT Seite 3
copper
aluminium
ferrousmaterials
chilled cast iron
grey cast iron
technical pureiron (C < 0,1%)
steel(0,1% C < 2%)
cast iron(2% < C < 4,5%)
white cast ironwhite iron white-heart
malleablecast iron
black-heartmalleablecast iron
lamellar
globular
nonferrousmaterials
Survey of materials for casting
others(magnesium,
tin, etc.)
annealedcast iron
3
© WZL / IPT Seite 4
The golden sun wagon of Trundholm, Seeland
Trundholm, Højby, Holbæk, Dänemark
14th cent. b. chr. bronze and goldlength: 59,6 cm
source: Nationalmuseum, Kopenhagen
Sun wagon - Early bronze period
© WZL / IPT Seite 5
Production of high-volume components through casting
Abrasive blasting process of a 16-cyl.- motor unit
made of GJL-300 (CrCu-alloyed) in a completely encapsulated
sand blast chamber with dust extraction set
source: Siempelkamp, Krefeld, konstruieren+giessen 3/94
4
© WZL / IPT Seite 6
Production of small-volume components through casting
Precsion casting component foran surgical instrument
material: G-X 10 CrNi 18 8 (1.43.12)dimension: ∅ 7 x 54 mm
weight: 10 g
source: Hitzbleck
© WZL / IPT Seite 7
source: Honsel
process: magnesium diecasting
material: EN-MC MgAl6Mn
thickness ofwalls: 2 - 2,5 mm
weight: 3,5 kg
Prototype of a cast car door made of magnesium
5
© WZL / IPT Seite 8
source: Eisenwerke Brühl
Motor unit- AUDI 059 2.5 L TDI: Audi A6, A4, A8, Passat
Cast part Part with machined surfaces
© WZL / IPT Seite 9
Boeing Instrument Panel - Aluminium investment casting
source: Tital
Dimensions1700x600x1200 mm
6
© WZL / IPT Seite 10
Structure of the lecture CastingIntroduction: Variety of applicationsBasics of casting
- Cooling down the liquefied material- Crystallization and crystal growth - directional
solidification- Basics of solidification- Casting simulation: Example
Production sequence at casting
Production of casting patternsProduction of consumable moulds and coresCasting processesCase studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
© WZL / IPT Seite 11
Cooling curve of pure iron resp. Fe-C (723°C)
Body-centeredcubic (b.c.c.)α- and γ-iron
Face-centeredcubicδ-iron
°C
15361392
911769723
210
molten mass
γ-Eisen, kubisch-raumzentriert
δ-Eisen (Austenit),kubisch-flächenzentriert
α-iron (ferrite), paramagnetic,body-centered cubic (b.c.c)
α-iron (ferrite), ferromagnetic
perlite
Fe3C (Zementit)ferromagnetisch6,67%C
source: Verlag Moderne Industrie - Temperguss
Cooling down the liquefied material: Changing crystal latticeElementary cell of thecrystal system
7
© WZL / IPT Seite 12
Crystallization and crystal growth
art-own nuclei foreign nuclei(e.g. contamination
Crystal growth
no. of nuclei direction ofheat-removal
rate of cooling
crystal size,crystal form
Crystal growth 180° opposite to the heat-removal
Crystallization nuclei
© WZL / IPT Seite 13
exclusivelyglobulites
Crystal nuclei are uniformly distributed
exclusivelyfringe crystals
Primary nucleationat side walls
Transition between both extreme examples
fringe crystals+
globulitessource: Spur, Handbuch der Fertigungstechnik, S.60
Formation of cast structure through crystallization
8
© WZL / IPT Seite 14
globuliticalsolidification
fringe crystalsolidificaton
monocrystallinesolidification
schematiccast structure
Directional a.monocrystalline solidification at turbine blades
source: Thyssen
© WZL / IPT Seite 15
200 µm
longitudinal transverse
longitudinal transversal
Cast structure after polycrystalline and directionalsolidification
200 µm 50 µm
1. polycrystalline
50 µm200 µm200 µm
2. Directional solidif.
9
© WZL / IPT Seite 16
3. monocrystalline solidificated
identical in longitudinal and transverse direction
Cast structure after monocrystalline solidification
200 µm 50 µm
© WZL / IPT Seite 17
Structure of the lecture CastingIntroduction: Variety of applicationsBasics of casting
- Cooling down the liquefied material- Crystallization and crystal growth - directional
solidification- Basics of solidification- Casting simulation: Example
Production sequence at castingProduction of casting patternsProduction of consumable moulds and coresCasting processesCase studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
10
© WZL / IPT Seite 18
number of nuclei
rate of cooling
formation ofcoarse grain
formation offine grain
coarse grain
fine grain
-
+
tensilestrength
- +
deformationresistance
hardness creep rate
-
+
-
+
-
+
directionaldependance
+
-
Grain size in the cast structure - Coarse grain and fine grain
© WZL / IPT Seite 19
Solidification of a hypoeutectique alloy
tem
pera
ture
T
percent in weight B
bd
S
a+SS+ß
a
Legend
a: alloying composition
b: primary crystallization
c: eutectic crystallization
d: eutectic alloy
a
c
source: Spur, Handbuch der Fertigungstechnik, S.60
11
© WZL / IPT Seite 20
smooth wallsolidification
rough wallsolidification
sponge likesolidification
example: pure metals
increase of alloy content
Exogenous solidification
fest flüssig
Solidification process - Crystallization at side walls
source: Engler, in: Spur, Handbuch der Fertigungstechnik
solid liquild
© WZL / IPT Seite 21
pulpysolidification
shell formatingsolidification
Endogenous solidification
source: Engler, in Spur, Handbuch der Fertigungstechnik, S.61
Solidification process - Crystallization inside the melt
12
© WZL / IPT Seite 22
inititial state
side wall movement
metal wall movement
Interface between metaland forc
concave planar
legend: a: die cavity b: die c: liquid metal (arrows show the direction of the movement)
Wall movement during solidification of cast iron
source: Spur, Handbuch der Fertigungstechnik, S. 75
konvex
a b
c
© WZL / IPT Seite 23
mould filling capacity
fluidity
feeding capacity
heat checking
Shrinkagecavitation
temperature
spez
ific
volu
me
32
1
temperature
spez
ific
volu
me
32
1
Shrinkage behaviour of pure metalsand eutectic alloys
Shrinkage behaviour of non-eutectic alloys
2 3
1
Casting properties - shrinkage cavitation
liquidshrinkage
solid
liquid
solidificationshrinkage
shrinkagecavity
so lid shrinkage
13
© WZL / IPT Seite 24
mould filling equation of continiuity:
Navier-Stokes-equation:
heat transport:solidification
with
source: konstruieren+giessen 23 (1998) Nr.3
Basic equations of heat and mass transfer
0)( =⋅vdiv rρ
( ) vpgradgvdivvv rrrr∆⋅++⋅=⋅⋅+⋅ µρρρ )(
[ ] [ ].
)()( QTgraddivTgradvTcp +⋅=⋅+⋅ λρ r
ngravitatiogvelocityvpressurepdensity
====
r
ρ
/.
heatofsourceQ
ductivitythermalconetemperaturT
heatspezificcitykineticvisµ
p
=
==
==
λ
cos
© WZL / IPT Seite 25
Contribution to casting simulation - Cast part
source: Magma
14
© WZL / IPT Seite 26
source: Magma
Contribution to casting simulation - Simulation of mould filling
© WZL / IPT Seite 27
Introduction: Variety of applications
Basics of casting
Production sequence at casting- Classification according to DIN 8580- Definitions of moulding and casting processes- The route to the structural cast part
Production of casting patterns
Production of consumable moulds and cores
Casting processes
Case studies: Simulation during design and production
Case study: Rapid-Prototyping used at production of casting patterns
Comparison of costs
Summary
Structure of the lecture Casting
15
© WZL / IPT Seite 28
Primary shaping
Primary shaping out of the gaseous or
vapour state
Primary shaping outof the liquid, pulpy or paste like state
Primary shaping outof the ionized statethrough electroly-
tical deposition
Primary shaping outof the solid, granular
or powdery state
casting inconsumable
moulds
casting inpermanent
moulds
permanentpatterns
consumablepatterns
powder metallurgy
lecture 2
source: DIN 8550
Classification of primary shaping methods acc.
© WZL / IPT Seite 29
Definitions: Moulding and casting processes
moulding process all processes for the production of consumable moulds, which arenecessary for the absorption of the liquid metal
static casting (gravity casting)
dynamic casting
movement of the mould
movement of the melt
consumable mould
permanent mould
sand casting
gravity die casting
movement of the mould and melt
centrifugal casting
pressure die casting
continuous castingsource: Spur
casting process principle of mould filling, e.g. gravity casting, pressure diecasting, ....
16
© WZL / IPT Seite 30
Structure of the lecture CastingIntroduction: Variety of applications
Basics of casting
Production sequence at casting- Classification according to DIN 8580- Definitions of moulding and casting processes- The route to the structural cast part
Production of casting patterns
Production of consumable moulds and cores
Casting processes
Case studies: Simulation during design and production
Case study: Rapid-Prototyping used at production of casting patterns
Comparison of costs
Summary
© WZL / IPT Seite 31
legend:
a
b
c
d
e
f g i
h
j k l
mn
source: Spur
The route to the structural cast part
a: cast patternb: hand mouldingc: machine mouldingd: core setting
e: core mouldingf: setting the top box of
the mouldg: castingh: melting
i: shaking outj: casting cleaning roomk: machining of cast partl: shipping
m: sand bunkern: sand plant
17
© WZL / IPT Seite 32
• Schmelzbetrieb
Example of application: Moulding shop
source: Gießerei Fronberg
© WZL / IPT Seite 33
source: Gießerei Fronberg
Example of application: Hand core moulding
18
© WZL / IPT Seite 34
unloading the cores out of the core shooter core setting
source: Laempe
Example of application: Automatisation at core production
© WZL / IPT Seite 35
machining deep-hole drilling
Example of application: Machining of cast parts
source: Gießerei Fronberg
19
© WZL / IPT Seite 36
Structure of the lecture Casting
Introduction: Variety of applications
Basics of casting
Production sequence at casting
Production of casting patterns
Production of consumable moulds and cores
Casting processes
Case studies: Simulation during design and production
Case study: Rapid-Prototyping used at production of casting patterns
Comparison of costs
Summary
© WZL / IPT Seite 37
production of consumable moulds
production of permanent moulds
generation the most important outer sections of the die cavity includingcore marks as well as casting and feed system
setting of core marks for fixing the cores (necessary for cast parts with cavitity)
pattern-materialrequirements
resistance against- mechanical stress (compression, beat loose, unloading the model)- chemical stress (humidity, acids and bases of the binding agents, gases)- thermal stress (heating of the model plate - necessary for hardeningof the moulding material)
good machinability
high surface quality
low density
woodmetal
plasticspolystyrene
tasks of the casting pattern
Tasks of casting pattern - pattern-material requierments
20
© WZL / IPT Seite 38
Milling a component of the casting patternDrawing of gearbox case cap
Production of a metal mould
© WZL / IPT Seite 39
Structure of the lecture CastingIntroduction: Variety of applications
Basics of casting
Production sequence at casting
Production of casting patterns
Production of consumable moulds and cores- Production of consumable moulds: Definitions and
example of application- Core production: Cold-Box und Hot-Box-process
Casting processes
Case studies: Simulation during design and production
Case study: Rapid-Prototyping used at production of casting patterns
Comparison of costs
Summary
21
© WZL / IPT Seite 40
mouldcategory
pattern
mouldcavity
consumablepattern
compression
mouldingmethod
split one piece
permanent moulds consumable moulds
hollow hollow solid
chemical chemical physical
smeltable gasifiable
precisioncasting
full mould-casting
dry sand-partial vacuum,
full mould-magneticmoulding
mechanical chemical physical
smectitesand-,method
cement-,waterglass-
plaster mouldcastings
air-Set-,Hot-Box,
Cold-Box-shell mould-
casting
Classification of methods for producing consumable moulds
source: Spur
© WZL / IPT Seite 41
Overview of mould materials for consumable moulds
granular basis moulding material(e.g. silica sand)
bond clay additives
waterclay-bonded
moulding materials62%
greensand methoddry-moulded
castingchamotte
moulding method(burning process at 600-800°C)
moulding method
resin-bondedmoulding materials,
cold-curing19,5%
cement-bondedmoulding materials
12%
resin-bondedmoulding materials,
heat-curing4,8%
water glass bondedmoulding materials
20%others
5%
source: Spur
22
© WZL / IPT Seite 42
basis moulding materialse.g. quartz sand, zircon sand
moulding material bindere.g.silicates, artificial resins
moulding material additivese.g. dust coal and synth.
glance coal agent to reduce the wettability
moulding materials(classification acc. to binder type)e.g.: clay- or water bonded sand
moulding methodclassification according to technology,
e.g. greensand method, (cold-box) and hot-box method
part of a molde.g. core, top and bottom box of a mold, shell
moulding adjuvantse.g. moulding powder, core binder
mould coating materialse.g. blackening, mould varnish
moulding accessoriese.g. central gate, cooling fixture
final mouldsource: Spur
Terminology of mould materials for consumable moulds
© WZL / IPT Seite 43
Process characteristics:The loose moulding sand is filled into the mould area formed by pattern plate/pattern bolster, mouldbox and filling frame. An air current is passed through and then the mould is compacted. The air current flows through the sand from the back of the mould in the direction of the pattern andescapes through vents in the pattern plate. The air current moves the sand into the less accessibleregions of the pattern and greatly improves and optimises compaction. The final strength in the mould is built up in an after-pressing stage, using a fixed or a flexiblepressure plate, a water cushion or a multi-platen press. The magnitude of the press pressure, as wellas the pressure and duration of the air current can be controlled. This enables optimum mouldstrengths to be achieved to suit the individual application.
principleSEIATSU™ Airflow Squeeze technology
for clay-bonded sand
example of application: cast part
Production of sand moulds using the SEIATSU™-process
source: HWS – Heinrich Wagner Sinto
23
© WZL / IPT Seite 44
Structure of the lecture Casting
Introduction: Variety of applications
Basics of casting
Production sequence at casting
Production of casting patterns
Production of consumable moulds and cores- Production of consumable moulds: Definitions and
example of application- Core production: Cold-Box und Hot-Box-process
Casting processes
Case studies: Simulation during design and production
Case study: Rapid-Prototyping used at production of casting patterns
Comparison of costs
Summary
© WZL / IPT Seite 45
The cold-box process is a core production method, at which humid, pourable moulding materialis cured (baked) in very short times at room temperature in cold core boxes.
core shooting introduction of gas disposal
sand-bindermixture
core
catalyst/airor CO2
thinned acidsource: Spur
Core production using cold-box method
24
© WZL / IPT Seite 46
Core production using hot-box method
B: Offenes SystemA: Geschlossenes System
transport of core sand to the
coreshooting machine
core sanddressing
core shooting inin heated core box
unloadingthe core
post-cure
source: Spur
curing of mouldingmaterial
in hot die
A: closed system B: open system
legend:
a: from the generatorb: outgoing air into
exhauster or in open airc: exhausterd: coree: core box
© WZL / IPT Seite 47
Examples for hot-box cores on furan resin basis
single cores and assembled cores for an aluminiumsuction system of a 6-cylinder injection engine
source: Spur
25
© WZL / IPT Seite 48
Cores and machining allowance at cast partone piece core
unmachined cast part with core
machining allowance
finishedcast part
source: Heidenreich & Harbeck
© WZL / IPT Seite 49
Introduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processes
- Casting in consumable moulds with permanent patterns- Survey of different processes- Sand casting process- Shell casting process
- Casting in consumable moulds with consumable patterns- Casting in permanent moulds without patterns
Case studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
Structure of the lecture Casting
26
© WZL / IPT Seite 50
Process Hand moulding
Possiblematerials
Weights (mass)rough values
Quantities,rough values
single parts,small batch series
typical part
Machine moulding Shell casting Shaw-process
all metals all metals
up to several tons, restricted by the sizeof the machinery
small batch series up tolarge-batch production
no restriction,available transportationequipment and meltingcapacity determine theupper limit
2,5% up 5% 1,5% up 3% 1% up 2% 0,3% up 0,8%
pump case piston rings ribbed cylinder head hip-joint implate
all metals all metals
up to 150 kg
medium batch series up to large-batch production
up to 1000 kg
single parts, smallbatch up to mediumbatch series
tolerance rangefor 500 mm nomi-nal size (*)
(*) : The specified tolerances are rough values for a nominal size of about ca. 500 mm; they depend on the grade of accuracy, the part size and the material. Material related tolerance specification see also DIN1680 and DIN 1683 up to DIN 1688. source: ZGV
Survey: Casting in consumable moulds with permanent patterns
© WZL / IPT Seite 51
Structure of the lecture CastingIntroduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processes
- Casting in consumable moulds with permanent patterns- Survey of different processes- Sand casting process- Shell casting process
- Casting in consumable moulds with consumable patterns- Casting in permanent moulds without patterns
Case studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
27
© WZL / IPT Seite 52
Work flow of the sand casting process
source: ZGV
bottom box
moulding plate withhalf of the pattern
top box
core mark
bottom box
inserted core
feeder feederdownsprue
cast part
© WZL / IPT Seite 53
Driving wheel for a belt drivematerial: GJL-300diameter: 2850 mm
Base of a vertical boring and turning millmaterial: GJL-200diameter: 5800 mmweight: 44 t
Examples for application - Sand casting (hand moulding)
source: konstruieren+giessen 2/2000
28
© WZL / IPT Seite 54
Example of application - Components of a ship‘s propolsionprocess: sand castingmaterial: CuAl9Ni7
CuAl10Fe5Ni5weight: 1 propeller blade ca. 1300 kg
hub ca. 3000 kg
blade
hub
source: Zollern
© WZL / IPT Seite 55
Casting in sand at a semi-automatic moulding facility
source: konstruieren+giessen 2/2000
29
© WZL / IPT Seite 56
Pump case made of low alloy GJL-300single weights: 362 resp. 144 kg
Example of application: Pump case - sand casting
source: konstruieren+giessen 2/2000
© WZL / IPT Seite 57
Truck wheel hub (light weight design)nodular cast iron GJS-400-15weight: 17.6 kg
Differential castingnodular cast iron
Crankshaftnodular cast ironGJS-600-3weight: 13.4 kg
source: Georg Fischer, Mettmann
Example of application: Power transmission - sand casting
30
© WZL / IPT Seite 58
Example of application: Aluminium sand casting
Suction inletAl - sand casting, G-AlSiCu3weight: 16.8 kg
Oil panAl - sand casting / G-AlSiMg(wa)weight: 4.5 kg
Clutch housingAl - sand casting / G-AlSi9Cu3weight: 44.6 kg
source: Georg Fischer, Friedrichshafen
© WZL / IPT Seite 59
Structure of the lecture CastingIntroduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processes
- Casting in consumable moulds with permanent patterns- Survey of different processes- Sand casting process- Shell casting process
- Casting in consumable moulds with consumable patterns- Casting in permanent moulds without patterns
Case studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
31
© WZL / IPT Seite 60
dW/d1 = 1,5
1: 250° hot pattern board 2: pre-baked shell mould 3: tilting the excessive mould material
moulding material
4: curing the shell mould 5: lift-off fixture 6: joining press
450 °C
7: casting of the mould on a casting bed
Work flow of the shell casting process
source: ZGV
© WZL / IPT Seite 61
Example of application: Shell casting process
metal pattern board casting mould and cast parts
source: UG Metal, Dk
32
© WZL / IPT Seite 62
Structure of the lecture CastingIntroduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processes
- Casting in consumable moulds with permanent pattern- Casting in consumable moulds with consumable patterns
- Survey of different processes- Investment casting- Full mould casting
- Casting in permanent moulds without patterns
Case studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
© WZL / IPT Seite 63
Process Investment casting
Possiblematerials
Weights (mass)rough values
Quantities,rough values
small batch series up tolarge-batch production
typical part
Full mould casting
all metals
1 g up to several kg(in special cases up to 100 kg)
0,3% up to 0,7% 3% up to 5%
turbine wheels machine base
all metals
no restriction (availabletransportation equip-ment), specially suitable for heavy transports
single parts, small batchseries (at suitable partsseries production)
tolerance rangefor 500 mm nomi-nal size (*)
(*) : The specified tolerances are rough values for a nominal size of about ca. 500 mm; they depend on the grade of accuracy, the part size and the material. Material related tolerance specification see also DIN1680 and DIN 1683 up to DIN 1688. source: ZGV
Survey: Casting in consumable moulds with consumable patterns
33
© WZL / IPT Seite 64
Structure of the lecture CastingIntroduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processes
- Casting in consumable moulds with permanent pattern- Casting in consumable moulds with consumable patterns
- Survey of different processes- Investment casting- Full mould casting
- Casting in permanent moulds without patterns
Case studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
© WZL / IPT Seite 65
Work flow of the investment casting process - part 1
production of a wax pattern
joining single waxpattern to „clusters“
each wax cluster is robotically dipped intoa ceramic slurry, drained, and then coated
with fused silica sand
injection dies withwax pattern
ceramic dippingbaths ensure a firm ceramic cover
source: ZGV, Feinguss Blank
34
© WZL / IPT Seite 66
Work flow of the investment casting process – part 2
dewaxing baking of the ceramicshell mould
pouring the liquidmaterial in the ceramic shell
removing theceramic shell
about 1400°C inthe furnace
filling the preheated shell mould with liquid metal at ~1200°C
separating thecastings is always
done manuallysource: ZGV, Feinguss Blank
© WZL / IPT Seite 67
source: Zollern
Removing the wax pattern from the injection moulding die
35
© WZL / IPT Seite 68
Design guideline - curved channels
Kern
splitting splitting
= direction, into which the core slides are removed
Curved channels are particularly cost-effective, when they can be producedwith core slides inside the workpiece.
In all other cases, water-soluble or ceramic cores have to be used.
source: Zollern
© WZL / IPT Seite 69
ingate
The number of ingates can be reduced through placing cut-outs⇒ reduction the grad of bulkiness the effort during casting
possible favourableingate ingate
saved ingate
Design guideline - reduction of ingates
36
© WZL / IPT Seite 70
Two-piece wax pattern for a pump case part
source: Zollern
Composite patternsjoining splitted patterns usingfitting-marks
undercut-contures possible
at symmetrical patterns which consist of two parts, only one injection moulding die is necessary
© WZL / IPT Seite 71
filter eyematerial: G - X5 Cr Ni Mo Nb 18/10
turbine wheelsmaterial: G - X5 Cr Ni Mo Nb 18/10
Wax injection moulding with cermaic cores Wax patterns and cast parts
source: Zollern
Examples for wax patterns and respective cast parts
37
© WZL / IPT Seite 72
Steering knuckle mademade of 1.7744 (tempered steel); 6,0 - 8,0 kg
Turbine wheels and nozzle rings made of Ni-base-alloys, weight: 1,3 - 3,0 kg
Load carrier and holder for landing flapmade of 1.7744, weight: 3,2 and 4,0 kg
Different structural partsfor aircraft turbine engine hydraulicsmade of pretici-pation-hardened, corrosion-resistant steel,weight: 0,4 - 2,3 kg
Examples for investment casting parts: Aerospace applicat.
source: Thyssen
© WZL / IPT Seite 73
Steel investment cast parts made of G-X6CrNi 18.9.Parts of a component insertion machine, which are exposed with accelrating power up to 3,5 g.
Examples for investment casting parts: High-tech components
source: Thyssen, konstruieren+giessen 25 (2000) Nr.4
Top holder:dimensions: 165 x 150 x 190 mmmaterial: 1.4308 (G-X6CrNi 18.9)weight: 1340g Portal S 50
dimensons: 600 x 305 x 95 mmmaterial: 1.4308
(G-X6CrNi 18.9)
weight: 6800g
38
© WZL / IPT Seite 74
Examples for investment casting parts: Engineering industry
Head peace of a pneumticnailing machinematerial: GS-15 CrNi6 (1.5919)dimensions: 80x80x128 mmweight: 800 g
Lever for a packingmachinematerial: GS-42 CrMo4
(1.7225)dimensions: 215x115x107 mmweight: 6,3 kg
Casing for a hydraulicsystemmaterial: GS-45 CrMo4
(1.0443)dimensions: 215x115x107 mmweight: 1,9 kg
source: ZGV
© WZL / IPT Seite 75
Spiral pump casing –food processing industrymaterial: G-X 5 CrNiMoNb 18 10 (1.4581)dimensions: 245 x 265 x 30 mmweight: ca. 7 kg
Valve chambermaterial: GS-38 (1.0416)weights of pieces: up to 30 kg
source: Thyssen
Examples for investment casting parts
39
© WZL / IPT Seite 76
Compressor impellermaterial: G-X 5 CrNiMo 16 5 (1.4405)weight: 16 kg
Casing, impeller and cap for a pump used in thfood processing industrymaterial: G-X 5 CrNiMoNb 18 10 (1.4581)diameter of casing: 220 mmweights of pieces: up to 4,5 kg
source: Thyssen
Examples for investment casting parts
© WZL / IPT Seite 77
Hip-joint implantsmaterial: G-TiAI6V4
Implants for hip and knee jointsmaterial: G-TiAI6V4
Examples for investment casting parts: Medical engineering
source: Tital
40
© WZL / IPT Seite 78
Structure of the lecture CastingIntroduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processes
- Casting in consumable moulds with permanent pattern- Casting in consumable moulds with consumable patterns
- Survey of different processes- Investment casting- Full mould casting
- Casting in permanent moulds without patterns
Case studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
© WZL / IPT Seite 79
Work flow of full-mould casting
source: ZGV
consumablefoamed plastic pattern
pattern embeddedin a one-piecemoulding box
without core!
without burrs!
41
© WZL / IPT Seite 80
Pattern made of polystyrene foam for a base of a machine tool (casting company) dimensions: 4800 x 2300 x 1650 mmweight of cast part: 9,5 tmaterial: EN-GJL-300 (GG-30, Ferrocast)
Foamed plastic pattern for a base of a machine tool
source: konstruieren+giessen 3/99
© WZL / IPT Seite 81
Structure of the lecture CastingIntroduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processes
- Casting in consumable moulds with permanent pattern- Casting in consumable moulds with consumable patterns- Casting in permanent moulds without patterns
- Survey of different processes- Diecasting- Permanent mould casting- Centrifugal casting- Continuous casting
Case studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
42
© WZL / IPT Seite 82
Survey: Casting in permanent moulds without patternsProcess Diecasting
Possiblematerials
Weights (mass)rough values
Quantities,rough values
series productionservice life of dies:Zn: 500.000 castingsMg: 100.000 castingsAl: 80.000 castingsCu: 10.000 castings
typical part
Permanent mould casting Centrifugal casting Continuous c.
diecasting alloys onAl-, Mg-, Zn-, Cu-, Sn-or Pb-base (ferrousmaterials in development)
light alloys, specialcopper based alloy, high-purity zink, lamellar andnodular graphite cast ironup to 100 kg(in special cases alsohigher)
series productionservice life of dies:Al: 100.000 castings
Al-alloy.: up to 50 kgZn-alloy.: up to 20 kgMg-alloy.: up to 15 kgCu-alloy.: up to 5 kg(restricted by the size of the diecasting machine)
0,1% up to 0,4% 0,3% up to 0,6% 1% 0,8%
oil pan, gera case piston tubes profiled bars
lamellar and nodular graphite cast iron,cast steel, light alloys,copper based alloys
,lamellar and nodular graph.cast iron,Cu-alloys
up to 5000 kg
series produciton,service life of dies:5000 up to 100.000 pc.depents on part size,casting material andtype of the die
depends oncross section, up to severaltons
lengt of castbillet dependson machine
tolerance rangefor 500 mm nomi-nal size (*)
(*) : The specified tolerances are rough values for a nominal size of about ca. 500 mm; they depend on the grade of accuracy,the part size and the material. Material related tolerance specification see also DIN1680 and DIN 1683 up to DIN 1688.source: ZGV
© WZL / IPT Seite 83
Structure of the lecture CastingIntroduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processes
- Casting in consumable moulds with permanent pattern- Casting in consumable moulds with consumable patterns- Casting in permanent moulds without patterns
- Survey of different processes- Diecasting- Permanent mould casting- Centrifugal casting- Continuous casting
Case studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
43
© WZL / IPT Seite 84
Principle of a hot-chamber diecasting machine
closing cylindertoggle mechanism(interlock)
core plate(moveable)
Clampingframe diecasting
mould
cavity plate(fixed)
injection cylinder
press ram
filling chamber
melting crucible
extrusion die (nozzle)
© WZL / IPT Seite 85
Hydro-mechanical cold-chamber diecasting machine
source: ZGV
a: closing cylinderb: round nutc: head plated: toggle levere: ejector cylinder
f: toggle link carrierg: core plate (moveable)h: pillari: ejector diek: cover die
l: cavity plate (fixed)m: pressure chambern: injection shot cylinder
legend:
44
© WZL / IPT Seite 86
source: Schimpke, Schroop
Operation cycle at cold-chamber diecasting process
I. III.
II. IV.
© WZL / IPT Seite 87
Arrangement of core pullers at diecasting mould
source: Schimpke, Schroop
filling port
cover die
ejector die
distributer core
core puller 3core puller 2
core puller 1
45
© WZL / IPT Seite 88
Classification of the process: cold-chamber diecastingRange of VACURAL parts: high quality production of thin
walled Al- and Mg-parts of high strength
Examples of applicationthin walled parts of the car body
as alternative to metal forming technologies
Principle of VACURAL™-diecasting method
source: Müller-Weingarten
legend:1 holding furnace 5 stationary platen 9 runner2 suction pipe 6 stationary die half 10 solenoid valve3 injecton chamber 7 vacuum valve 11 vacuum pump 4 injection piston 8 moveable die half 12 vacuum tank
© WZL / IPT Seite 89
source: Härer-Werkzeugbau
Example of application - diecasting: Truck oil pan and die
46
© WZL / IPT Seite 90
gear casematerial: aluminium diecasting
AlSi9Cu3weight: 5.4 kg
Torque converter housing HP500, ZFmaterial: aluminium diecasting
AlSi9Cu3dimensions: 542 x 553 x 553 mmwall thickness: 3,5 - 25 mmweight: 41,0 kg
source: (1) Georg Fischer, Herzogenburg; (2) Honsel
Example of application - diecasting: Gear case and converter
© WZL / IPT Seite 91
Structure of the lecture CastingIntroduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processes
- Casting in consumable moulds with permanent pattern- Casting in consumable moulds with consumable patterns- Casting in permanent moulds without patterns
- Survey of different processes- Diecasting- Permanent mould casting- Centrifugal casting- Continuous casting
Case studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
47
© WZL / IPT Seite 92
Work flow at permanent mould casting
melting casting heat treatment machining quality control
Casting in permanent mould!
mould materíal: - hot forming tool steel- heat resisting special alloys
source: Gontermann-Peipers
© WZL / IPT Seite 93
Principle of a two-piece casting die with core
core puller runner gate
feeder
cast part1st mould half
2nd mould half
48
© WZL / IPT Seite 94
Principle of low-pressure permanent mould casting
compressed-airp ~ 1,5 bar
casting die
graphite melting pot
heating
transformer coil
cast pot
feed tube
cooling air
© WZL / IPT Seite 95
Examples of application - Permanent mould castingSchmelzen Gießen
Wärmebehandlung
source: Gontermann-Peipers
millingcircular table
melting casting
heat treatment
49
© WZL / IPT Seite 96
Example of application - Aluminium permanent mould casting
Gear casealuminium permanent mould castingmaterial: G-AlSi10Mg(wa)weight: 17.0 kg
Slide part of a chassis / left and rightaluminium permanent mould castingmaterial: GK-AlSi7Mg(wa)weight: 2.1 kg / 2.1 kg
source: Georg Fischer, Mettmann
© WZL / IPT Seite 97
expenditure of work and material; transport effortand energy expenseper workpiece
risk to produce scrap
thin walls of cast partspossible
fine grain
automatable
permanent mould casting casting in sand
+ -
- +
+ -
+ -
+ -
Comparison of permanent mould casting and casting in sand
50
© WZL / IPT Seite 98
Structure of the lecture CastingIntroduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processes
- Casting in consumable moulds with permanent pattern- Casting in consumable moulds with consumable patterns- Casting in permanent moulds without patterns
- Survey of different processes- Diecasting- Permanent mould casting- Centrifugal casting- Continuous casting
Case studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
© WZL / IPT Seite 99
mould
metal sand lining
rotation axis
horizontal vertical
cooling
cooled not cooled
Examples:
a, c: metal mould with horizontalrotation axis, without cooling
b: metal mould with core andvertical rotation axis,without cooling
a)
b)
c)
source: Spur
Differentiating criteria at centrifugal casting
51
© WZL / IPT Seite 100
Production of pressure pipes with centrifugal casting
stationaryrotational cylinder sand lining
core for sleeve cam roller
gate channel
foundry ladle
© WZL / IPT Seite 101
Centrifugal- und gravitational force at centrifugal casting
source: Spur
Fres
FCG
FresG
FC
Fres
G FC
A
Fres = FC - G
Fres = FC - G
G
M
G
Fres
FC
FC
Fres
e
Division of forces within the meltat horizontal centrifugal casting
Position of liquid metal in the permanent mouldat different rotationl speeds of the centrifugal casting machine
v1 v2 > v1
v3 > v 2 v4 > v 3
52
© WZL / IPT Seite 102
Example of application: Materials at centrifugal cast part
examples for materials(acc. to Gontermann-Peipers):
lamellar graphite cast iron acc. to EN 1561 (prior DIN 1691)
nodular graphite cast iron acc. to EN 1563 (prior DIN 1693)
austenitic cast iron acc. to DIN 1694
alloyed cast iron qualities acc. tocustomers request
machinig of a circular cast cylinder sleeve
source: Gontermann-Peipers
© WZL / IPT Seite 103
Examples of application: Centrifugal casting
source: GTR
source: IPO, Sophia
53
© WZL / IPT Seite 104
Structure of the lecture CastingIntroduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processes
- Casting in consumable moulds with permanent pattern- Casting in consumable moulds with consumable patterns- Casting in permanent moulds without patterns
- Survey of different processes- Diecasting- Permanent mould casting- Centrifugal casting- Continuous casting
Case studies: Simulation during design and productionCase study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
© WZL / IPT Seite 105
foundry case
gate pot
permanent mould
cooling water
water spraying
driving pulleyscutting-off deviceblock tilter
Principle of vertical continuous casting
54
© WZL / IPT Seite 106
gate pot
permanent mould
cooling water
driving pulleys
Principle of horizontal continuous casting
source: Gontermann-Peipers
liquid metal
© WZL / IPT Seite 107
Structure of the lecture Casting
Introduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processesCase studies: simulation during design and production
- Starting point: FE-analysis and tool design- Simulations- Critical areas at the cast part- Results of optimization
Case study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
55
© WZL / IPT Seite 108
new aluminium wheel is designed
Production by using the low-pressure permanent mould casting process
Simulation should help to reduce casting defects up front
- optimization of casting design for improved quality
- optimization of mould tempering for improved quality
The residual stress in the as cast condition should be considered atthe FE-analysis
principle low-pressure permanent mould castingsource: Magma
Casting simulation and process optimization at Al-wheel
© WZL / IPT Seite 109
Product Planning Production
CAD, CAE, FE Analysis, Casting Simulation
source: Magma
Integrated CAE technologies support simultaneous engineering
Kic
k O
ff
Func
tiona
l D
esig
n
Det
aile
d D
esig
n
Tool
ing
Proc
ess
Des
ign
Prot
otyp
ing
Prod
uctio
n
Qua
lity
Con
trol
56
© WZL / IPT Seite 110
Casting design: 3D CAD construction of the new Al-wheel
source: Magma
© WZL / IPT Seite 111
FE-analysis of the cast part
150 MPa
0 MPa
Stress and distortion under test load (3.500N in 630mm distance of the mounting plate).
The maximum stress value is about 80MPa.
150 MPa
0 MPasource: Magma
57
© WZL / IPT Seite 112
Casting design - Tool geometry
top core
bottom coreand slide
source: Magma
© WZL / IPT Seite 113
Tool and cooling channelscooling channel
cooling channel
die sections
ingate
source: Magma
58
© WZL / IPT Seite 114
Structure of the lecture Casting
Introduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processesCase studies: simulation during design and production
- Starting point: FE-analysis and tool design- Simulations- Critical areas at the cast part- Results of optimization
Case study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
© WZL / IPT Seite 115
Temperatures during filling
source: Magma
59
© WZL / IPT Seite 116
Solidification sequence
source: Magma
© WZL / IPT Seite 117
Cooling measureswater, 30°C
casting sectionsair, 60°C
ingate
air, 30°C
All cooling channels with individual time control
source: Magma
60
© WZL / IPT Seite 118
Tool temperatures - closed die
source: Magma
© WZL / IPT Seite 119
Tool temperatures - before openingHigh tool temperatures mean low heat reduction from the casting
source: Magma
61
© WZL / IPT Seite 120
Tool temperatures - upper core opens
slides open
source: Magma
© WZL / IPT Seite 121
Tool temperatures - before closing the die
tool closes again
source: Magma
62
© WZL / IPT Seite 122
Tool temperatures - closed tool, before next cycle
source: Magma
© WZL / IPT Seite 123
Structure of the lecture Casting
Introduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processesCase studies: simulation during design and production
- Starting point: FE-analysis and tool design- Simulations- Critical areas at the cast part- Results of optimization
Case study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
63
© WZL / IPT Seite 124
Critical section for feedingDensity between 90% and 100%
pores
Solidification time between 10s and 80s
hot spots
source: Magma
© WZL / IPT Seite 125
Residual stress and total deformation 1 (3)The residual stress is in the order of magnitude of the stress caused by the test load
source: Magma
150 MPa
0 MPa
64
© WZL / IPT Seite 126
150 MPa
0 MPa
Residual stress and total deformation 2 (3)Residual stress plus load stress…
150 MPa
0 MPa
source: Magma
© WZL / IPT Seite 127
Residual stress and total deformation 3 (3).... results in the total stress under load, that can be in the range
of the yield strength.
150 MPa
0 MPa
source: Magma
65
© WZL / IPT Seite 128
Structure of the lecture Casting
Introduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processesCase studies: simulation during design and production
- Starting point: FE-analysis and tool design- Simulations- Critical areas at the cast part- Results of optimization
Case study: Rapid-Prototyping used at production of casting patternsComparison of costsSummary
© WZL / IPT Seite 129
Density between 90% and 100%
Solidification time between 10s and 80s
strongly reduced porosity
better feeding through the spoke
Output of optimization: Reduced porosity and better feeding
source: Magma
66
© WZL / IPT Seite 130
Summary of the simulation case study „Al-wheel“The integrated casting simulation / FE-analysis of the original wheel design provided thefollowing information:
– casting defects due to hot spots and insufficient feeding would occur– the addition of residual stress and test load would lead to maximum total stress values above the yield
strength
Optimization measures have been worked out– tapering to support feeding– thicker spokes to support feeding and to reduce the maximum stress values
The optimization measures were proofed by casting simulation and FE-analysis
source: Magma
© WZL / IPT Seite 131
Structure of the lecture Casting
Introduction: Variety of applicationsBasics of castingProduction sequence at casting Production of casting patternsProduction of consumable moulds and coresCasting processesCase studies: simulation during design and productionCase study: Rapid-Prototyping used at production of casting patterns
- Starting point and result of optimization Comparison of costsSummary
67
© WZL / IPT Seite 132
Design if possible right-angled !No big and abrupt change of cross section!Designing the cells in the same size !Avoid that ribs run together at one node!Minimum wall thickness at cast part: 20 mm!
length: 1400 mmwidth: 500 mmheight: 150 mm
transverseacceleration: 2 gdeformation: 4 µm
production: o.k.
length: 1400 mmwidth: 500 mmheight: 150 mm
transverseacceleration: 2 gdeformation: 4 µm
production: o.k.
Example of application: High speed supporting table (1)
source: Heidenreich & Harbeck
© WZL / IPT Seite 133
Load orientated ribbing
deformation: -50 %mass: -15 %costs: -10 %
Load orientated ribbing
deformation: -50 %mass: -15 %costs: -10 %
source: Heidenreich & Harbeck
Example of application: High speed supporting table (2)
length: 1400 mmwidth: 500 mmheight: 150 mmweight: 140 kg
transverseacceleration: 2 gdeformation: 2 µmEN-GJS-400-18
length: 1400 mmwidth: 500 mmheight: 150 mmweight: 140 kg
transverseacceleration: 2 gdeformation: 2 µmEN-GJS-400-18
68
© WZL / IPT Seite 134
conventional Rapid-Prototyping
drawing
tool
wax pattern
investment casting
cast part
ca. 6 weeks
ca. 6 weeks
Σ = 12 weeks
CAD-Data
Rapid-Prototypingpattern
investment casting
cast part
ca. 1 week
Σ = 4 weeks
ca. 3 weeks
Production time of Al-precision cast parts-conventional and RP
source: Tital
© WZL / IPT Seite 135
Quickcast - ModellGear Case VW / Wolfsburg
cast partmaterial:GF-AlSi7Mg0,6weight: 18 kg
Example of application: Pattern for a gear case
source: Tital
69
© WZL / IPT Seite 136
Structure of the lecture Casting
Introduction: Variety of applications
Basics of casting
Production sequence at casting
Production of casting patterns
Production of consumable moulds and cores
Casting processes
Case studies: simulation during design and production
Case study: Rapid-Prototyping used at production of casting patterns
Comparison of costs
Summary
© WZL / IPT Seite 137
Comparison of manufacturing costs for a gear case
number of produced parts
200 100 300 1000
man
ufac
turin
g co
st in
dex
of d
iffer
ntm
anu-
fact
urin
gm
etho
ds, i
nclu
ding
all
extr
a ch
arge
s
0
100
200
300
400
%
casting in sand
investmentcasting conventional
cutting processes
cast part: pump casematerial: aluminium-alloy
diecasting
70
© WZL / IPT Seite 138
manufacturing
manufacturing costs 100 % 50,5 %
material titanium
costs for fixtures resp. tools 100 %
costs for material
costs for machining resp. assembling
mass 4500 g
100 %
100 %
titanium
4400 g
64,6 %
96,5 %
3,9 %
assembling of 9 milled parts investment casting
1- prior ⇒ 2 - today
1 2
Investment casting contra assembling: Aerospace application
source: Tital
© WZL / IPT Seite 139
Structure of the lecture Casting
Introduction: Variety of applications
Basics of casting
Production sequence at casting
Production of casting patterns
Production of consumable moulds and cores
Casting processes
Case studies: simulation during design and production
Case study: Rapid-Prototyping used at production of casting patterns
Comparison of costs
Summary
71
© WZL / IPT Seite 140
Explain the change of the crystal lattice during cooling down the liquefied material at the example of pure iron!
Outline and explain the globulitical, fringe crystal and monocrystalline solidification at turbine blades!
Coarse grain contra fine grain!
Nominate and explain different casting properties (5)! What is meant with „shrinkage cavitation“ and how does that casting damage arise?
How are the moulding and casting processes defined?
Nominate and explain different methods of core production!
Into which main groups (3) are the casting processes classified?
Explain the principal work flow of the casting processes which belong to the three main groups!
Nominate and explain the essential parts of a casting simulation!
Explain the proceeding of the rapid-prototyping process for production of casting patterns!
Catalogue of questions to summarize the lecture „CASTING“
© WZL / IPT Seite 141
Structure of the exercise Casting
Introduction
Requirement oriented design of cast parts- Casting faults- Shape and casting oriented design- Load oriented design- Machining oriented design
Film: Presentation and definition of casting processes
Exercises- Requirement oriented design of cast parts- Selecting a casting process